[How valid are student self-reports of bullying in schools?].

In this study we examine the reliability and validity of students' self-reports about bullying and victimization in schools. 208 5th class students of four "middle schools" in Southern Germany filled in the Bully-Victim-Questionnaire (Olweus, 1989, adapted by Lösel, Bliesener, Averbeck, 1997) and the School Climate Survey (Brockenborough, 2001) to assess the prevalence of bullying/victimization, and to evaluate attitudes towards aggression and support for victims. By using reliability and validity criteria, one third (31%) of the questionnaires was classified as "unreliable/invalid". Mean comparisons of the "unreliable/invalid" group and the "valid" group of the subscales concerning bullying/victimization found significant differences. The "unreliable/invalid" group stated higher values of bullying and victimization. Based on the "unreliable/invalid" questionnaires more students could be identified as bullies/victims or bully-victims. The prevalence of bullying/victimization in the whole sample was reduced if "unreliable/invalid" questionnaires were excluded. The results are discussed in the framework of theories about the presentation of the self ("impression management', "social desirability") and systematic response patterns ("extreme response bias").